On Mon, Sep 11, 2017 at 2:47 AM, Jan Kara <jack@suse.cz> wrote:> On Fri 08-09-17 12:35:13, Dan Williams wrote:>> The mmap(2) syscall suffers from the ABI anti-pattern of not validating>> unknown flags. However, proposals like MAP_SYNC and MAP_DIRECT need a>> mechanism to define new behavior that is known to fail on older kernels>> without the support. Define a new MAP_SHARED_VALIDATE flag pattern that>> is guaranteed to fail on all legacy mmap implementations.>>>> With this in place new flags can be defined as:>>>> #define MAP_new (MAP_SHARED_VALIDATE | val)>> Is this changelog stale? Given MAP_SHARED_VALIDATE will be new mapping> type, I'd expect we define new flags just as any other mapping flags...> I see no reason why MAP_SHARED_VALIDATE should be or'ed to that.

True, it will just by a new MAP_TYPE plus new flags. I will fix this up comment.